Draftsman&#39;s spacing device



May 14, 1957 E. RICHTER 2,791,838

DRAFTSMANS SPACING DEVICE Filed March 22, 1955 2 Sheets-Sheet l May 14,1957 E. RICHTER 2,791,838

DRAFTSMANS SPACING- DEVICE Filed March 22. 1955 2 Sheets-Sheet 2DRAFTSMANS SPACING DEVICE Ernst Richter, Farmingdale, N. Y.

Application March 22, 1955, Serial No. 495,995

2 Claims. (Cl. 33-110) The present invention relates to draftrnansspacing devices of the character which will accurately determine asuccession of positions of a drafting implement for the purpose ofdrawing lines such as section lines or other lines requiring periodicequal spacing.

A further purpose Vis to facilitate step by step motion of a draftingimplement along a T square or other straight edge or across a piece ofdrawing paper or a drawing board or template.

A further purpose is to accomplish the spacing with simple, reliable andinexpensive mechanism.

Further purposes appear in the specification and in the claims.

In the drawings I have chosen to illustrate one only of the numerousembodiments in which my invention may appear, selecting the form shownfrom the standpoints of convenience in illustration, satisfactoryoperation and clear demonstration of the principles involved.

Figure 1 is a perspective of the spacing device of the invention.

Figure 2 is a section along the line 2-2 of Figure l.

, Figure 3 is a side elevation partly `in section along the line 3-.3 ofFigure 4.

` Figure 4 is -a fragmentary plan view showing the device of theinvention applied to a T square with an associated triangle.

aired States Patent Figure 5 is a central axial section on the line S-Sof Figure 4 similar to Figure 3 but showing the foot in the relativeforward position with respect to the base where Figure 3 shows the footrelatively rearward with respect to the base.

Figure 6 is a perspective of a variation.

Describing in illustration but not in limitation and referring to thedrawings:

In drafting, both inking and pencil work, in making jigs and templates,in spacing center marks for drilling holes, it is lfrequently necessaryto produce a large number of lines which `are equally spaced. This maybe necessary for the purpose of sectioning or for other purposes inmaking drawings, or to locate holes, or for projection. This work hasbeen very tedious when applied with accurate measurement, leading to thepractice of putting in lines by estimation, which is some cases leads tovery inaccurate work.

The device of the invention makes it possible to obtain 1accuratestep-by-step spacing in a simple, reliable and effective manner.

In accordance with the invention, each step advances the implement apredetermined but adjustable step disstance, so that the mechanism canbe set for any desired predetermined spacing.

The spacing device may be applied directly to the drawing paper or tothe drawing board or template, but will preferably be used on la Tsquare or other straight edge. It may operate either longitudinally ortransversely or at an angle, as desired.

The mechanism of the invention comprises a body or base 20 which maysuitably be of wood, plastic or metal and desirably has a lower surfacecovered with a frictional material such as leather or felt 21. Thefrictional material is desirably chosen so as to limit free sliding butnot prevent sliding when positive force is applied.

The body Ztl is recessed at the interior at 22 to form an interior wellhaving longitudinal guiding side walls Z3 which receive and guide a foot24 suitably of wood, metal or plastic as desired, and covered with africtional layer 25 on the bottom which may similarly be of leather orfelt having properties as above described. The foot is capable ofraising and lowering slightly and moving back and forth while engagingthe guiding walls 23. It will be noted that the plan area of the foot isless than that of the body.

The body 'at the rear of the device supports a bracket 26 ex-tendingupward and at the top mounting a transverse horizontal pivot pin 27which pivots a bellcrank operating lever 2S. The bellcrank operatinglever has a top lever portion Si) provided with an operating button 31for engagement by the hand and which is suitably positioned nearly abovethe center of the foot. The button 3i is conveniently recessed at 32 sothat the iinger will not slip off and is held by a rivet 33.

The operating lever has lower extending ends 34 which engage stops 35 onthe bracket and the opera-ting lever is urged toward stop position by atortion spring 36 having a coil surrounding the pivot pin 27 and havingan end 37 engaging the lower side of the operating lever and an opposedend 38 which rests on the top of a transverse pivot pin 4t) mounted onbrackets 41 which .are secured to the body on either side of the openingcontaining the foot.

The operating lever at the outer end has a suitably metallic extension42 which engages a follower roller 43 pivotally mounted on a pin 44which extends across a slotted second lever 45 suitably of L-shape. Thesecond lever intermediate its ends rests and slidingly pivots on pivotpin 4G and is held lagainst pivot pin 46 by a leaf spring 46 engagingthe lower side of pivot pin 40 and mounted on a bracket 47 on the bottomof the second lever.

The end of the second lever 45 remote from the follower roller issuitably slotted at 43 and mounts a transverse pivot pin 5th whichpivotally connects to a suitable L-shaped link $1. The link 51 has abranch 52 extending upward and a branch 53 which extends in scissorsrelation through the slot 4S, engaging the under side of pivot pin 4t),and at the opposite end pivotally engages in a pin S4 which extendsacross a slot S5 in the foot. The pivot pin is ancho-red in place by aslotted cover plate 56 secured to the top of the foot.

The foot is relatively retracted forwardly by helical tension spring 57,which `at the forward end engages spring abutment 58 on the body and atthe rearward end engages spring abutment t) on the foot. Spring abutment60 has a head 6i at the top and extends through a longitudinal slot 62on a limiter strip 63 which at the forward end is slotted a-t 64 andheld in adjustable position by an adjustment screw 65 secured to thebody.

The body at suitable points on the top and suitably on either s idecarries screw holes 66 which receive retaining screws 67 which securebrackets 68 having slots 70 engaged under the screws. The brackets atthe outer ends have screws 71 which are suitably anchored as byengagement in holes in a drafting implement, for example a triangle 72,whose lower edge 73 is in slidable relation with one of the longitudinaledges 74 of T-square 75 having cross arm 76.

On the opposite side of the body, screw 77 secures spring 78 whichextends down along the opposite longitudinal side 80 of the T square andspring urges the triangle into maintaining engagement with the T square.

In operation, the adjustment screw 65 is released and the adjustmentstrip 63 is set so that the limit on motion of the foot as shown inFigure 3 will predetermine the correct step distance between lines, andthen screw 65 is tightened. The triangle or the like is secured as byapplying screws 71 in suitable holes in the triangle and securingbrackets 68 by screws 67. The spacing device is then placed in positionalong the straight edge and the device is ready to operate. The operatorpresses down on button 31, depressing operating lever 30 as far as itwill go 'against the action of spring 36. This forces follower roller 43down and tends to rock second lever 45 counterclockwise to the positionshown in Figure 3, causing the rearward end of the second lever todelect the link counterclockwise, moving the foot 24 relatively rearwardwith respect to the body and at the same time applying relativelygreater pressure to the foot than the pressure on the body. The effect,therefore, is to tend to make the foot hold due to its higher pressure,while the body having a larger pressure area but being under a lowerpressure, slides forward as shown in Figure 3. In effect the foot staysstill and the body moves forward while extending the tension spring 57.

When the pressure of the linger is released from the button 31, spring36 tends to move the operating lever 28 clockwise until it is limited bythe stop 35. Spring 57 retracts the foot with respect to the body to theposition of Figure 5, and at the same time the pressure on the foot isrelaxed and the foot is free to raise slightly due to the weight of thedevice and slide forward. The link 51 and the second lever 45 areretracted to the position of Figure 5.

During all of this step by step motion, slight sliding occurs betweenthe second lever and the link with respect to pivot pin 40, the scissorsor crossing relation of the second lever and the link and the action ofleaf spring 46 tending to hold the second lever and the link against thepivot pin.

Thus it will be evident that when pressure is applied downward at aposition close above the foot and near the center of the body the eifectof the linkage is to apply relatively higher pressure on the foot andrelatively lighter pressure on the body and move the body forward whileholding the foot stationary. When the pressure von the operating leveris relieved the body remains stationary and the foot moves forwardbecause the concentration of pressure downward on the foot is relieved,the foot is pulled forward and the larger bottom engaging area of thebody holds the body stationary.

Thus accurate step by step motion can be obtained. The draftsman willbring the triangle or other drafting implement to the position for therst line, draw the iirst line, and then press down on the button andallow the button to retract moving the device to the position for thenext line. The next line is drawn and then the button is pressed againand allowed to retract, moving to the position for the next line. Fordifferent spacing it is merely necessary to adjust the strip 63 bychanging the position of adjustment screw 65.

When locating holes, a center punch 81 mounted on spring strip 68receives a hammer blow to make a center punch mark at each steprofadvance on the work. The strip is held by screw 67.

In view of my invention and ldisclosure variations and modifications tomeet individual whim or particular need will doubtless become evident toothers skilled in the art, to obtain all or part of the benelits of myinvention without copying the structure shown, Iand I, therefore, claimall such insofar as they fall within the reasonable spirit and scope ofmy claims.

Having thus deseribedmy invention what I claim as new and desire tosecure by Letters Patent is:

1. In a draftsmans spacing device, a body slidable along a drawing boanior the like, and having an interior opening, a foot positioned in theinterior opening of the body, and slidable along the drawing board,means for guiding the foot in relative forward and backward mo tion withrespect to the body, an operating lever pivotally mounted on the bodyand swingably movable from a position above the foot toward and lawayfrom the foot, a second lever operatively engaging the operating levernear its end remote from the pivotal mounting, a link pivotallyconnected to the second lever at the end of the second lever remote fromthe engagement of the second lever with the operating lever, the linkbeing pivotally connected to the foot at the end of the link remote fromthe second lever, and a slidable |pivot on the body for the second leverand the link, whereby the foot advances Iand retracts with respect tothe body and concurrently shifts relative pressure from the foot to thebody and vice versa.

2. A spacing device of claim 1, in which the second lever and the linkextend in scissors relation and the slidable pivot is located betweenthe crossing parts of the second lever and the link.

References Cited in the le of this patent UNITED STATES PATENTS 14,396Eickemeyer Mar. 11, 1856 125,115 Bergner Apr. 2, 1872 2,052,904 StahlSept. 1, 1936 2,510,439 Van Doorne et al June 6, 1950 FOREIGN PATENTS91,901 Switzerland Dec. 1, 1921 652,244 Germany Oct. 27, 1937

